Patent GB-384380-A (GB)
Title: Improvements in and relating to photographic cameras
IPC: G03B15/00
Filed: 1931-09-16
Abstract: 384,380. Photographic camera apparatus. WILLIAMSON, C. M., Cascade Works, Litchfield Gardens, Willesden Green, London. Sept. 16, 1931, Nos. 25962/31 and 17064/32. [Class 98 (i).] In a camera especially for use on aircraft, of the type having mechanism for automatically actuating the shutter and winding the film, the shutter is actuated by a single revolution of a shaft driven by a spring connected at one end to a spring drum and at the other to a member rotated by hand or power means for loading the spring, means being provided to limit the relative movement of the parts to one revolution per cycle. The camera comprises a body, a lens cone in which the shutter is mounted, a film magazine, an instrument box and a gear box mounted on the side of the body and the shutter and film winding mechanism are operated from clutches the complementary parts of which are in the gear box and in the lens cone and magazine and the pressure plate is actuated by a reciprocating member in the gear box. In the form shown, the actuating mechanism comprises a shaft 6, Fig. 5, on which are sleeved a mutilated gear 10 and a spring drum 8 carrying a bevel wheel 7, a spring 11 on the drum 8 being connected to the gear 10. Stops on the gear 10 and drum 8 limit their rotation to one revolution and reverse movement of the gear 10 is prevented by a pawl 10a. The gear 10 is connected through gearing 12, 14 to a vertical shaft 14b coupled through a clutch to a shaft 63, Fig. 8, in the film magazine. The supply and take up spools 53, 54 are supported at the rear end on rollers 55 on springy arms 56, and the take up spool 54 is supported at the front end by a shaft 58 driven through a friction clutch 61 from a pinion 60 meshing with a pinion 62 driven from the shaft 63. The pinion 62 also drives a feed roller 65. The supply spool is carried at the front end by a shaft 68 bearing an indicating disc 70 showing when the film is in motion. The sleeves 9 on the main shaft 6 carries a recessed cam 15 on which runs a roller 16 carried by an arm 17 which actuates a plunger 27. The pressure plate 48, Fig. 6, is carried by a lever 49 pivoted at one end, the free end engaging under a spring plunger 52 operated by the plunger 27. The plunger 52 also operates a pawl by which an exposure counter 76, Fig. 8, is stepped on, and is locked in position when the magazine is removed from the body by a hook 77a on a bell-crank lever 77 engaging a projection 77b on the plunger. The bell crank is released by a stud 77c, Fig. 4, on the gear box. The release lever 20 is operated either from a Bowden control 32, acting on a bell crank 31, by a solenoid 35 the core of which is connected to the bell crank 31 or directly by hand through an aperture 30 in the casing of the gear box. The lever 20 carries a lug 22 engaging a slot 23 in the drum 8 to lock it in position during winding. Upon actuation of the lever 20 the lug 22 enters a slot 24 in the wheel 10 locking it and releasing the drum 8. Winding is effected in known manner by a remote windmill, an electric motor or by hand. The shutter is of the type described in Specification 365,224, and is operated by the bevel wheel 7 through a clutch the corresponding parts of which are in the gear box and lens cone. The instrument box 4 is fitted into the side of the camera body and contains a counter 79a, a watch 79b, a compass 79c and a barometer 79d each having a lens and an electric lamp intermittently lighted by a dashpot switch of the type described in Specification 370,721, [Group XXXVII], set by the movement of the plunger 27. Remote control of the type described in Specification 222,548, [Class 98 (i), Photographic cameras &c.], may be used. In a modification the gear 10 is toothed all round and drives a spiral gear 93, Fig. 12, meshing with a spiral gear 94 on the shaft 14b which is slidable and carries a collar 95 engaging rollers on the arm 17, so that a clutch 97 is unmeshed to disconnect the film feed when the roller 16 on the arm 17 drops into the recess in the cam 15. Specification 175,449, [Class 98 (i), Photographic cameras &c.], is also referred to in connection with the use of a mutilated gear.